When we get an ACK we should close DHCP sockets so we don't handle any NAKs

during ARP testing.

This is important as some broken DHCP servers NAK immediately after an ACK
in some situations.

diff --git a/dhcpcd.c b/dhcpcd.c
index daf4e0bada4c270a5e8edb612b87f9dee6313705..31d0634469f0473ebcce57afd877c665904b1ddb 100644 (file)
--- a/dhcpcd.c
+++ b/dhcpcd.c
@@ -497,7 +497,8 @@ handle_dhcp(struct interface *iface, struct dhcp_message **dhcpp)
                lease->addr.s_addr = dhcp->yiaddr;
                lease->server.s_addr = INADDR_ANY;
                if (type != 0)
-                       get_option_addr(&lease->server.s_addr, dhcp, DHO_SERVERID);
+                       get_option_addr(&lease->server.s_addr,
+                           dhcp, DHO_SERVERID);
                log_dhcp(LOG_INFO, "offered", iface, dhcp);
                free(state->offer);
                state->offer = dhcp;
@@ -551,6 +552,11 @@ handle_dhcp(struct interface *iface, struct dhcp_message **dhcpp)
        lease->frominfo = 0;
 
        delete_timeout(NULL, iface);
+       /* We now have an offer, so close the DHCP sockets.
+        * This allows us to safely ARP when broken DHCP servers send an ACK
+        * follows by an invalid NAK. */
+       close_sockets(iface);
+
        if (ifo->options & DHCPCD_ARP &&
            iface->addr.s_addr != state->offer->yiaddr)
        {